/*
    SDL - Simple DirectMedia Layer
    Partial implementation of SDL library (originally written by
    Sam Lantinga <slouken@libsdl.org>) for the particular purpose to support
    Prequengine (http://code.google.com/p/prequengine/) on BlackBerry(tm)
    tablets and smartphones.

    Copyright (C) 2013  xlamsp

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

    xlamsp@gmail.com
*/

#ifndef SDL_RWOPS_H_
#define SDL_RWOPS_H_

#include "SDL_stdinc.h"
#include "SDL_error.h"


/** This is the read/write operation structure -- very basic */

typedef struct SDL_RWops {
    /** Seek to 'offset' relative to whence, one of stdio's whence values:
     *  SEEK_SET, SEEK_CUR, SEEK_END
     *  Returns the final offset in the data source.
     */
    int (*seek)(struct SDL_RWops *context, int offset, int whence);

    /** Read up to 'maxnum' objects each of size 'size' from the data
     *  source to the area pointed at by 'ptr'.
     *  Returns the number of objects read, or -1 if the read failed.
     */
    int (*read)(struct SDL_RWops *context, void *ptr, int size, int maxnum);

    /** Write exactly 'num' objects each of size 'objsize' from the area
     *  pointed at by 'ptr' to data source.
     *  Returns 'num', or -1 if the write failed.
     */
    int (*write)(struct SDL_RWops *context, const void *ptr, int size, int num);

    /** Close and free an allocated SDL_FSops structure */
    int (*close)(struct SDL_RWops *context);

    Uint32 type;
    union {
        struct {
            int autoclose;
            FILE *fp;
        } stdio;
        struct {
            Uint8 *base;
            Uint8 *here;
            Uint8 *stop;
        } mem;
        struct {
            void *data1;
        } unknown;
    } hidden;

} SDL_RWops;


/** @name Functions to create SDL_RWops structures from various data sources */
/*@{*/
extern SDL_RWops * SDL_RWFromFile(const char *file, const char *mode);
extern SDL_RWops * SDL_RWFromFP(FILE *fp, int autoclose);
extern SDL_RWops * SDL_RWFromMem(void *mem, int size);
extern SDL_RWops * SDL_AllocRW(void);
extern void SDL_FreeRW(SDL_RWops *area);
/*@}*/

/** @name Seek Reference Points */
/*@{*/
#define RW_SEEK_SET     0       /**< Seek from the beginning of data */
#define RW_SEEK_CUR     1       /**< Seek relative to current read point */
#define RW_SEEK_END     2       /**< Seek relative to the end of data */
/*@}*/

/** @name Macros to easily read and write from an SDL_RWops structure */
/*@{*/
#define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence)
#define SDL_RWtell(ctx)                 (ctx)->seek(ctx, 0, RW_SEEK_CUR)
#define SDL_RWread(ctx, ptr, size, n)   (ctx)->read(ctx, ptr, size, n)
#define SDL_RWwrite(ctx, ptr, size, n)  (ctx)->write(ctx, ptr, size, n)
#define SDL_RWclose(ctx)                (ctx)->close(ctx)
/*@}*/

/** @name Read an item of the specified endianness and return in native format */
/*@{*/
extern Uint16 SDL_ReadLE16(SDL_RWops *src);
extern Uint16 SDL_ReadBE16(SDL_RWops *src);
extern Uint32 SDL_ReadLE32(SDL_RWops *src);
extern Uint32 SDL_ReadBE32(SDL_RWops *src);
extern Uint64 SDL_ReadLE64(SDL_RWops *src);
extern Uint64 SDL_ReadBE64(SDL_RWops *src);
/*@}*/

/** @name Write an item of native format to the specified endianness */
/*@{*/
extern int SDL_WriteLE16(SDL_RWops *dst, Uint16 value);
extern int SDL_WriteBE16(SDL_RWops *dst, Uint16 value);
extern int SDL_WriteLE32(SDL_RWops *dst, Uint32 value);
extern int SDL_WriteBE32(SDL_RWops *dst, Uint32 value);
extern int SDL_WriteLE64(SDL_RWops *dst, Uint64 value);
extern int SDL_WriteBE64(SDL_RWops *dst, Uint64 value);
/*@}*/

#endif /* SDL_RWOPS_H_ */

